no spark on cylinder 4.

[Carl H]

as title states...heres where it stands:new plugschecked with a known good coilchecked with a known good ignitortested coil harness for continuty

drove fine for 200mi to school,parked it over night and it stopped sparking on cyl 4.im out of ideas.

[Bwana]

Compression? Fuel?

???

[Shocker]

so its getting a signal to the coil plug pack? You running and aftermarket ign system? and you are on a stock chipped ECU right?

[Carl H]

splitfire coils and power fc...problem developed literaly overnight.

[eh?]

Have you checked if you're getting voltage to the ignitor? You'll need a good analog meter or a o-scope. Check the FSM for the specs.

[Carl H]

well, ive exhausted all fault tracing i can except for ecu...i ran another wire to the ecu and clipped the suspect wire and it still is not sparking on cyl 4.

[Tictakman]

when was the last time u disconnected the power fc to the harness? ive reattached them and bent a pin causing it not to fire...

[Carl H]

definately didnt disconnect the pfc from the harness before i went to sleep...what i dont understand is that i have signal for the trigger, good continuity and power to the coils...it SHOULD fire.

[Coolwhip]

damaged or faulty harness connector at coil connection?

[Carl H]

thats the next course of action when i get back home...track down a working coil pack harness and try swapping that.

[jdmser]

Any progress on this? I've been hunting down my own little ignition gremlin with similar symptoms.
Modified by jdmser at 11:24 PM 8/29/2007

[mello88]

Carl, are you getting trigger signal before the ignitor? what about after the ignitor? If yes on both then you're probably on the right track with the coilpack connector..

[Carl H]

mellow88 - im getting the trigger signal but for some reason its somewhat weak, spec is .2-3v while running and the pfc is only generating .15v.im thinking that the pfc might be the problem due to the fact that the ignitor is nothing more than a series of transistors which in essence are diode setup to switch...trigger voltage is proly not being reached.

[eh?]

Did you try a stock ecu yet? Did you see if the trigger pulse each cylinder is in line?

[Carl H]

im at school right now so home is 200mi/3hrs away...gonna grab my stock ecu this weekend and give it a go.